Device for cleaning sewer pipe walls

ABSTRACT

A device for cleaning sewer pipe walls using a cleaning fluid is disclosed. The device includes a carriage and a nozzle carrier having a main axis disposed in the carriage. The nozzle carrier includes a hose connection and a plurality of nozzles disposed in the nozzle carrier around the main axis, where a respective nozzle axis of each of the plurality of nozzles runs obliquely to the main axis. The nozzle carrier is connected to the carriage in a rotationally fixed manner.

This application claims the priority of International Application No.PCT/DE2011/001712, filed Sep. 9, 2011, and German Patent Document No. 102010 044 953.9, filed Sep. 10, 2010, the disclosures of which areexpressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a device for cleaning sewer pipe walls using acleaning fluid comprising a carriage and a nozzle carrier having a mainaxis and arranged in the carriage, the nozzle carrier being providedwith a hose connection for the supply of cleaning fluid and a pluralityof nozzles for applying the cleaning fluid that are arranged in thenozzle carrier around the main axis, the nozzle axes of said nozzlesrunning obliquely to the main axis.

A device of this type whose objective is to remove the sludge and slimeadhering to the inner walls of a sewer pipe in a streak-free manner withas little fluid consumption and work effort as possible is described inGerman Patent Document No. DE 103 21 425 A1. In order to achieve this,the nozzle carrier is arranged in a carriage so that it can be rotatedaround the main axis of said nozzle carrier. The main axis runsapproximately in or parallel to the longitudinal axis of the sewer pipe.The oblique orientation of the nozzles produces a swirl, which allowsthe nozzle carrier to rotate around the main axis, and a friction brakeensures that the rotational speed does not get too high. The fluid jetis thereby guided in the circumferential direction over the sewer wall,which facilitates a streak-free cleaning of the pipe wall. It has beenshown that the mounting of the nozzle carrier in the carriage is verysusceptible to malfunctions and that the friction brake is difficult toadjust.

Therefore, the invention is based on the object of developing a devicefor cleaning pipe walls that has a simple design and operateseffectively.

To attain the object, the invention provides for the nozzle carrier tobe connected to the carriage in a rotationally fixed manner.

It has been shown that, even without a rotation of the nozzle carrieraround its main axis, it is possible to achieve adequate cleaning of thesewer pipe walls. It is precisely the oblique orientation of the nozzlesthat makes it possible for the jet to hit the pipe wall diagonally,i.e., with a radial component, whereby the jet assumes a spiral-shapedprogression on the pipe wall, thereby preventing streak formation inparticular.

The device is designed so that the nozzles are essentially directedtowards the rear, i.e., towards the hose connection. Therefore, the hosefastened to the hose connection is used, on the one hand, for supplyingthe fluid and, on the other hand, for inserting the device into a sewerpipe in that the thrust of the nozzles causes the device to advance inthe sewer and the hose is pulled along with it.

In order to achieve a deflection of the fluid in the nozzle carrier andat the same time produce a uniform supply for all obliquely disposednozzles, it is provided that the hose connection is connected to achamber in the nozzle carrier, with boreholes emanating from the chamberto the outer surface of the nozzle carrier into which the nozzles areinserted, and the chamber being delimited by a deflection surfaceopposite from the hose connection. Due to the axially symmetrical designof the deflection surface, the pressure is distributed to the nozzlesfree of turbulence.

The design of the device is especially simple if the nozzle carrier ismade of a base body and an annular nozzle head for accommodating theboreholes and the hose connection, with the deflection surface beingconfigured on an end face of the base body, and if the nozzle head isconnected to the carriage in a rotationally fixed manner, with the basebody being detachably connected to the nozzle head, but not directly tothe carriage. The oblique arrangement of the nozzles produces a momentof torque around the main axis. In order to prevent the nozzle head fromrotating, said nozzle head itself is arranged in the carriage in arotationally fixed manner, while the base body is detachably connectedto the nozzle head, but not directly to the carriage. The base body ispreferably screwed to the nozzle head by means of a thread runningcoaxially to the main axis.

In order to be able to moisten the region in front of the nozzle carrieror flush away coarse dirt, the base body has a longitudinal boreholeleading from the end face having the deflection surface to an exteriorend face, with a receptacle being provided there, which receives a plugprovided with nozzle boreholes. If it is possible to dispense with apreliminary cleaning, a solid plug sealing the longitudinal borehole maybe used instead of a plug having nozzle boreholes.

An especially intensive and streak-free cleaning of the pipe walls isachieved by nozzles disposed obliquely on the rear side of the nozzlecarrier, if the nozzles are arranged in two circles running coaxially tothe main axis. In this case, the nozzles are arranged on one circleoffset in the circumferential direction from the nozzles on the othercircle.

In addition, it may be provided that the nozzles on the outer circlehave a different degree of obliqueness than the nozzles on the innercircle, which means that the distance between the nozzle axes of thenozzles on the outer circle is greater than that of the nozzle axes ofthe nozzles on the inner circle. The distance in this case is the lengthof a distance vector which runs both perpendicularly on the main axis aswell as perpendicularly to the nozzle axis. This means that the nozzleson the outer circle form a jet spiral having a lower pitch on the wallsurface to be cleaned, the result being an overlapping of the spirals ofthe inner and outer circles, which intensifies the cleaning.

The inclination of the nozzle axes from the main axis should be equallylarge for the nozzles on the inner circle and for those on the outercircle.

Because the base points of the distance vector between the main axis andthe nozzle axes for all nozzles on a circle lie at the same location onthe main axis, the orientation of all nozzles on a circle is identical,so that the carriage can be used oriented in any direction in the pipeto be cleaned and always produces the same cleaning effect.

The invention is explained in more detail in the following on the basisof an exemplary embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal section through the device according to theinvention; and

FIG. 2 is a cross section through the device with a top view of thedouble circle of nozzles disposed obliquely to the main axis of thedevice.

DETAILED DESCRIPTION OF THE DRAWINGS

The device is made of a carriage 1 having four runners 2, which arefastened externally on a support ring 3 in a uniformly distributedmanner. The runners 2 that are distributed uniformly on a circumferencerun substantially parallel, with the ends thereof each being bentinwardly to develop a certain clearing effect.

A nozzle carrier 4 having a main axis 5 that is parallel to the runners2 is arranged inside the support ring 3. The nozzle carrier 4 is made ofa nozzle head 6 and a base body 7. The outer circumference of the nozzlehead 6 corresponds approximately to the inside diameter of the supportring 3 so that the nozzle head 6 is inserted there and held in arotationally fixed manner by means of headless screws 8. Situated on therear end face of the nozzle head 6 and arranged centrally is a hoseconnection 9 around which boreholes 12 for accommodating nozzle insertsare arranged on two circles 10, 11 running concentrically to the mainaxis 5. These may be designed as described in German Patent Document No.DE 10 2010 026 720 A1, the related content of which is incorporated intothe present application by reference. The nozzle inserts are designedsuch that the nozzles point in the direction of the nozzle axes 13depicted in the drawing.

The boreholes 12 emanate from a conical ring surface 14 on the rear sideof the nozzle head 6 and end in a stepped chamber 15, the side of whichthat is open toward the front side of the nozzle head 6 is sealed by thebase body 7, which is why said base body is screwed into the chamber 15.The rear end face of the base body 7, which delimits the chamber, formsa deflection surface 16 that is rotationally symmetrical to the mainaxis 5, which is why the base body 7 is provided with a central taper 17directed into the hose connection 9, the base of said taper beginning inan annular trough 18 that runs around the taper 17. The boreholes 12 foraccommodating the nozzle inserts are directed at the base of the taper17 or into the trough 18.

Running through the base body 7 in the main axis 5 is a longitudinalborehole 19, which ends at the outer end face in a receptacle for a plug20. The plug 20 that is screwed in there has nozzle boreholes 21, 22,and namely a central nozzle borehole 21, which is directed forward inthe main axis 5, as well as several lateral nozzle boreholes 22distributed around said central nozzle borehole and directed slightlyoutwardly. The front end face of the plug 20 lies somewhat outside thebent ends of the runners so that the jet is able to escape unhindered tothe front, thereby achieving a pre-cleaning of the pipe.

As FIG. 2 shows in more detail, the boreholes 12 for the nozzles lie ontwo circles 10, 11 coaxially to the main axis 5 of the device, and theboreholes 12 a for the nozzles on the inner circle 10 are offset fromthe boreholes 12 b for the nozzles on the outer circle 11. Because theaxes of the boreholes 12 a, 12 b are identical to the nozzle axes 13,the boreholes 12 a, 12 b will also be referred to as nozzles in thefollowing. Each circle 10, 11 has eight nozzles so that the distancebetween two nozzles that are offset from each other is 22.5°. Thenozzles are offset in turn from the runners 2 so that the jet escapingfrom the nozzle does not hit the runners 2. The angle of inclinationthat the nozzle axes 13 maintain with respect to the main axis 5 isapproximately 25° in the exemplary embodiment. The angle of inclinationis the angle between the nozzle axis projected at the main axis planeand the main axis, and the main axis plane is a plane in which the mainaxis lies and which runs perpendicularly to the distance vector betweenthe nozzle axis and the main axis. The nozzles are substantiallyoriented rearward and produce a feed motion. The nozzles in this caseare obliquely oriented, i.e., they do not lie in a plane through whichthe main axis 5 also runs, but in a plane offset therefrom; i.e., thenozzle axes have a radial component which can be determined in referenceto a nozzle plane which is produced by a rotation of the main axis planearound the main axis and in which the nozzle lies. The offset isselected in such a way that the nozzle axes enclose an angle of 5° to10° with the nozzle plane.

The orientation of the jets may also be defined via the distance of themain axis from the nozzle axes. The distance is the length of thesection which is perpendicular to both the main axis and the nozzleaxis.

Therefore, the fluid jets escaping from the nozzles hit diagonally tothe cylindrical wall surface of the pipe being cleaned, i.e., they havea radial component so that the jet deflected at the wall surfacetransitions into a spiral on the wall surface, expanding slightly in theprocess and removing adhesions from the inner wall of the pipe in aspiral-shaped band. This band may be relatively narrow so that the bandregion is cleaned intensively. But because the carriage advancesaxially, the spiral-shaped band is shifted progressively in the axialdirection so that the pipe wall is cleaned over its entirecircumference. Therefore, streak formation such as occurs with a purelyaxial orientation of the nozzles is prevented.

A device for cleaning sewer pipe walls is described in the present case.Water is normally used as the fluid. However, it is also conceivable touse the device for example in exhaust ducts that are required inkitchens to suction off greasy air. Also in this case, a greasy layerforms over time on the inner walls. For this purpose, air is used as thefluid. However, in order to develop sufficient separation force, thenozzles are likely to have a smaller diameter in this case than thoseused with water.

LIST OF REFERENCE NUMBERS

-   -   1 Carriage    -   2 Runners    -   3 Support ring    -   4 Nozzle carrier    -   5 Main axis    -   6 Nozzle head    -   7 Base body    -   8 Headless screws    -   9 Hose connection    -   10 Inner circle    -   11 Outer circle    -   12 a, b Boreholes    -   13 Nozzle axes    -   14 Ring surface    -   15 Chamber    -   16 Deflection surface    -   17 Taper    -   18 Trough    -   19 Longitudinal borehole    -   20 Plug    -   21 Central nozzle borehole    -   22 Lateral nozzle boreholes

1.-10. (canceled)
 11. A device for cleaning sewer pipe walls using acleaning fluid, comprising: a carriage; and a nozzle carrier having amain axis, wherein the nozzle carrier is disposed in the carriage;wherein the nozzle carrier includes a hose connection and a plurality ofnozzles disposed in the nozzle carrier around the main axis, wherein arespective nozzle axis of each of the plurality of nozzles runsobliquely to the main axis, and wherein the nozzle carrier is connectedto the carriage in a rotationally fixed manner.
 12. The device accordingto claim 11, wherein the hose connection is connected to a chamber inthe nozzle carrier, wherein a plurality of boreholes emanate from thechamber to an outer surface of the nozzle carrier, wherein each of theplurality of nozzles is disposed within a respective one of theplurality of boreholes, and wherein the chamber is delimited by adeflection surface opposite from the hose connection.
 13. The deviceaccording to claim 12, wherein the nozzle carrier includes a base bodyand an annular nozzle head for accommodating the plurality of boreholesand the hose connection, wherein the deflection surface is configured onan end face of the base body, wherein the nozzle head is connected tothe carriage in a rotationally fixed manner, and wherein the base bodyis detachably connected to the nozzle head and is not directly connectedto the carriage.
 14. The device according to claim 13, wherein the basebody is screwed to the nozzle head by a thread running coaxially to themain axis.
 15. The device according to claim 13, wherein the base bodydefines a longitudinal borehole leading from the end face to an exteriorend face, wherein the exterior end face includes a receptacle, andwherein a plug with a plurality of nozzle boreholes is disposed withinthe receptacle.
 16. The device according to claim 11, wherein theplurality of nozzles are disposed on a first circle and a second circlerunning coaxially to the main axis.
 17. The device according to claim16, wherein nozzles disposed on the first circle are arranged offsetfrom nozzles disposed on the second circle.
 18. The device according toclaim 16, wherein a distance between the axis of a nozzle disposed onthe first circle and the main axis is smaller than a distance betweenthe axis of a nozzle disposed on the second circle and the main axis.19. The device according to claim 16, wherein an angle of inclinationwhich encloses the plurality of nozzles with the main axis is equallylarge for the nozzles disposed on the first circle and the nozzlesdisposed on the second circle.
 20. The device according to claim 16,wherein base points of a distance vector between the main axis and theaxes for all nozzles disposed on the first circle or the second circlelie at a same location on the main axis.